I am in the middle of a job using CS 6, but at the same time opening the Creative Suite apps. I created an InDesign file in CS 6, saved it, and now I can't open it. I'm getting this message: Cannot open file because it was saved with a newer version of A

I am in the middle of a job using CS 6, but at the same time opening the Creative Suite apps.  I created an InDesign file in CS 6, saved it, and now I can't open it. I'm getting this message: Cannot open file because it was saved with a newer version of Adobe InDesign CC (10.1). You must use that version or later to open the file." AARRGGHH! So how do I access the file?